As a method for preventing a bitter taste or an unpleasant taste, addition of a flavored sweetener, manufacturing of a solid dispersion by using a spray dryer, shielding by using an ion exchange resin, melt extrusion, coating by fluidized bed water, and so forth have been known. In addition to that, various types of technologies, in which an active substance is coated with a polymer that is not dissolved in the oral cavity to prevent a patient from feeling a bitter taste in the oral cavity or the gullet when administered, have been known.
Korean Patent Application Publication No. 10-2004-0011087 a process for preparing roxithromycin granules having masked taste and smell” relates to a method of manufacturing a roxithromycin granule, which comprises granulating an active substance, roxithromycin, and then fine-coating the granulated roxithromycin, which in turn serves as a seed in coating with an agent and a plasticizer at low temperatures. The patent discloses that an unpleasant taste and flavor are masked and an active substance is released only in the stomach. Korean Patent Application Publication No. 2002-0069377 that has the invention title of “a process for preparing release-controlled granules of quinolone-based drugs having masked taste and smell” discloses a process in which an active substance is granulated and the taste and flavor are masked by using a fluidized bed water.
In accordance with the demand for novel medicinal products that can be easily taken and have improved convenience, various types of methods for manufacturing an orally disintegrating dosage form have been developed in many countries. Korean Patent Application Publication No. 2000-0016654 that has the invention title of “intraorally rapidly disintegrable tablet” discloses a method for manufacturing a tablet that contains sugar alcohol or sugars having an average particle diameter of 30 μm or less, an active substance, and a disintegrating agent. Korean Patent Application Publication No. 10-2004-0073288 that has the invention title of “solid orally-dispersible pharmaceutical formulation” discloses a method for manufacturing a solid orally dispersible pharmaceutical formulation comprising granules of co-dried lactose and starch and an active substance. In addition, Korean Patent Application Publication No. 10-2005-0096941 that has the invention title of “tablet quickly melting in the oral cavity” discloses a method of providing a tablet that has the hardness, which is considered to be desirable in practice, and rapidly integrates in the oral cavity. The above-mentioned prior arts disclose the methods for manufacturing the orally disintegrating dosage form, but they do not disclose how to mask a taste and a flavor of an active substance. When an orally disintegrating dosage form is manufactured according to the above-mentioned methods after an active substance having bitter or unpleasant taste is covered with the coating layer, the coating layer of the active substance is destroyed by pressure, thus a patient may feel the taste of the active substance. Thus, there is a disadvantage in that dosage and convenience performances may not be improved.
With respect to a method for protecting contents during tableting, U.S. Pat. No. 6,923,984 B1 that has the invention title of “Cushioning wax beads for making solid shaped articles” discloses a method for protecting wax beads containing an active substance by controlling the ratio of similar-sized cushioning wax beads. However, there are disadvantages in that it requires high shear mixing with temperature-control and that CO2 pellet needs to be supplied for temperature control.